I store pistol and rifle munitions in plastic ammo boxes (50 rd. count for pistol & 20 rd. for rifle). These are then packed in metal military surplus ammo cans (my preference is .50 cal). The military ammo cans are separated and labeled by ammo caliber.
I have yet to develop a logical approach to shotgun reloads. Therefore, they are all in 25 rd. factory cardboard packaging.